One key component of any computer system is a device to store data. Computer systems have many different places where data can be stored. One common place for storing massive amounts of data in a computer system is on a disc drive. The most basic parts of a disc drive are an information storage disc that is rotated, an actuator that moves a transducer to various locations over the disc, and electrical circuitry that is used to write and read data to and from the disc. The disc drive also includes circuitry for encoding data so that it can be successfully retrieved and written to the disc surface. A microprocessor controls most of the operations of the disc drive as well as passing the data back to the requesting computer and taking data from a requesting computer for storing to the disc.
In the disc drive industry, high-performance, thin-film storage discs produced by depositing successive layers on a substrate apparatus for preparation of such storage discs are well known in the art. For storage discs of the type formed on a rigid disc substrate, each layer in the storage disc may be deposited in a separate chamber. For example, the under-layer, the magnetic layer, and the over-layer (lubrication layer) are generally deposited in separate processing chambers. Generally, such layers are deposited onto the disc surfaces using sputtering processes.
Sputtering is a well known method of providing relatively uniform deposits of material on a substrate. Essentially, sputtering is accomplished by the impingement of gas ions on a cathode plate or target plate in the presence of an electrostatic field which causes particles of the cathode plate material to be dislodged therefrom. By appropriately positioning a substrate in the path of such dislodged particles, a deposit of cathodic material will be produced on the substrate. In a typical sputtering system the target (cathode) and substrate holder (anode) are positioned so that the surface of the substrate upon which the film is to be deposited is placed on the holder, facing the target.